1. Field of the Invention
The invention relates to wearing apparel and its manufacture and more particularly relates to the manufacture of elastomer coated garments.
2. Brief Description of the Prior Art
The prior art is replete with descriptions of textile wearing apparel such as gloves and their manufacture; see for example U.S. Pat. No. 3,173,150.
Elastomer coated garments such as work gloves are well known in the prior art. They are particularly useful for handling wet or toxic articles. It is particularly desirable to have a rough or wrinkle finish work garment, elastomer coated, for handling smooth articles having sharp edges such as for example, sheets of glass, castings with sharp edges and shiny metal sheets having sharp edges. For example, a wrinkle finish glove provides a higher resistance to abrasion and cutting by the sharp edges and also provides a more efficient gripping surface. The prior art method of obtaining a "wrinkle finish" on an elastomer coated textile glove comprises dipping, for example, a jersey knit fabric glove into the elastomer coating. Prior to full curing of the elastomer coating the coated glove is then dipped into a solvent which will cause the elastomer polymer to swell. This results in the wrinkle finish. The disadvantage of the prior art method resides in (1) the use of a hazardous solvent such as for example xylene, (2) the capital investment for equipment designed to handle solvent fumes and of course (3) the additional step of dipping the elastomer coated glove into the solvent. Further, the exposure of the elastomeric coating to a solvent weakens the polymer coating and reduces the life of the glove in regard to abrasion resistance. Those skilled in the art will also appreciate that the prior art method requires maturing of the elastomer latex material prior to its use. By maturing, we means that the elastomeric coating materials generally have to be aged at elevated temperatures for varying periods of time, dependent on the temperature, batch size, mixing and like variables, prior to their being used as a textile coating if they are to wrinkle properly. Therefore one can see that "wrinkle consistency" from batch to batch is normally difficult to control.
By the method of my invention, it is not necessary to employ hazardous solvents, nor is it necessary to employ a separate dipping step to obtain the desired wrinkle finish. Further, the garment prepared according to the method of my invention has enhanced resistance to abrasion, a longer life and provides a tougher, more resilient elastomeric coating without the need of maturing the coating material. These are economic advantages to the art. In addition, the most advantageous texture is obtained in the method of the invention, using relatively low viscosity coating compositions. Therefore the elastomeric coating composition requires little adjustment in the method of the invention, thereby shortening the compounding time and simplifying the procedure of the prior art. The ability to use relatively low viscosity elastomeric coating materials also reduces the possibility of web formation between the fingers of the gloves being coated and of air entrapment in the coating. The use of low viscosity materials also improves adhesion and wear. Unexpectedly, multiple dips, which are common on heavy garments to get the desired polymer coating weight, are not required in spite of the use of low viscosity coating compositions in the method of the invention. The coating weight is controlled by web weight. Thus the method of the invention allows one to design wearing apparel in such a way that the coating polymer may be concentrated wherever its presence is desired to be enhanced. This is achieved by placing the fibrous material where heavy coating weight is desired and not where a heavier weight is a detriment, i.e.; for example in gloves at the palm and knuckle areas. Those skilled in the art will appreciate that the method of the invention provides efficient use of the coating compositions.
In one embodiment of the invention, elastomer coated, wrinkle finish textile based garments are made from textile fabrics having an extraordinary long nap on the outer surface. In the prior art, textiles having a napped outer surface were coated with elastomeric materials by dipping. The napped surface was used primarily to improve adhesion of the elastomeric polymer film and to slightly increase the coating weight. The nap was the result of a finishing process that raises the fibers of the textile cloth by means of revolving cylinders covered with metal points or teasel burrs. Since the yarn used in the textile is generally made from twisted staple fibers, the nap is actually broken or frayed yarn which is short, with about 1/8 to 1/4 inch nap height, uniform and relatively dense. In dipped glove applications, the textile napped cloth is usually cotton and therefore the nap is a fine fiber, or low denier. Cotton is preferred in such applications because of its absorbent characteristics which will cause latex to coagulate by dehydration and prevent penetration through the cloth. This coagulation effect, along with a short, fine, dense rap will cause latex to form a heavy, uniform film, especially at normal viscosities. The result is a lack of a pronounced texture.
The use of a non-woven web has many obvious differences over the use of napped textile materials. Initially, the fibers from which the web is made are preferably synthetic and therefore wet completely and do not coagulate the latex. Furthermore, the fibers are more random in nature and tangle by needling. The fiber is also generally much longer, anywhere from 0.5 to 4.0 inches in length. Fiber coarseness or denier is relatively high at 6. Any denier may be used (from 1 to 15); however the higher the denier, the greater the texture since the high denier fiber will not mat down as will the low denier fibers. In addition, the web weight or density may be varied depending on a coating weight desired. In addition, the needling of a non-woven material to a textile base has an advantage over napped materials in that excessive napping of a conventional cloth to increase nap length or weight may cause holes or tearing of the cloth.
However, as employed in one embodiment of the invention, a textured effect may be accomplished by using a base fabric with an extraordinary long nap. As an example, with a pile or plush fabric, such as a terry cloth, velvet or corduroy made with a cotton face yarn (smooth side) to stop penetration and a synthetic pile yarn (nap side) one may achieve a similar textured effect when dipped. Pile or plush weaving results in a much higher nap than a conventional cloth. In general, the pile heights are on the order of from about 1/8 inch to about 1 inch. The long nap fabric would be used in construction of garment articles where texture and extra coating weight are desired.